The present invention is directed to an auxiliary control, and more specifically to an auxiliary control that provides for automated diagnostics.
Today, many automobiles include auxiliary controls that are located for operator convenience. These controls are often mounted in the steering wheel or within reach of a rear seat passenger to allow for remote control of a controlled device (e.g., an automotive entertainment system (e.g., a radio receiver) or heating ventilation and air conditioning (HVAC) system). Many of these auxiliary controls are based on a simple resistive divider network that provides a unique voltage to a controller for each button (i.e., switch) that is asserted. When no button is asserted, a typical auxiliary control provides a signal of zero volts (i.e., ground) to the controlled device on an auxiliary control input. Unfortunately, when such an auxiliary control is installed, a diagnostic/verification tester cannot determine if the auxiliary control is connected without technician intervention. In a typical situation, a technician has to physically activate a button (i.e., a switch of the auxiliary control) in order for the tester to determine if the auxiliary control is present.
As such, a technique for automatically detecting the presence of an auxiliary control, without human intervention, is desirable to verify correct assembly.
The present invention is directed to a method and system that automatically determines the presence of an auxiliary control. A controlled device includes a main control input and an auxiliary control input. If an auxiliary control is present, a discernible non-zero default signal is provided on the auxiliary control input of the controlled device when no inputs of the auxiliary control are asserted. This advantageously allows for the verification of correct assembly (i.e., determination of the presence or non-presence of an auxiliary control) without technician intervention.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawing""s.